If you have recently deleted your yahoo emails and those were really important for you then you can follow these steps to recover those emails.
- Go to Yahoo.com and log in your account
- Click on this link and click on "send restore request":- https://help.yahoo.com/kb/recover-lost-deleted-emails-sln2552.html
- Describe your problem on the next step and click on create request
- After that you will receive email from yahoo and then it will take 6-7 hours to recover your emails.
If you still face any problem then read this article:- How to recover permanently deleted yahoo emails